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Make sure callouts are not processed one tick late.

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The problem was introduced in SVN 180608/ rev 1.114 and affects
all users of callout_reset() (including select, usleep, setitimer).
A better fix probably involves replicating 'ticks' in the
struct callout_cpu; this commit is just a temporary thing so that
we can MFC it after a suitable test time and RE approval.

MFC after:	3 days
This commit is contained in:
Luigi Rizzo 2009-09-12 21:44:34 +00:00
parent fa2eebfce6
commit 446e861708
1 changed files with 2 additions and 2 deletions
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4
sys/kern/kern_timeout.c
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@ -244,7 +244,7 @@ callout_tick(void)
need_softclock = 0;
cc = CC_SELF();
mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET);
for (; (cc->cc_softticks - ticks) < 0; cc->cc_softticks++) {
for (; (cc->cc_softticks - ticks) <= 0; cc->cc_softticks++) {
bucket = cc->cc_softticks & callwheelmask;
if (!TAILQ_EMPTY(&cc->cc_callwheel[bucket])) {
need_softclock = 1;
@ -323,7 +323,7 @@ softclock(void *arg)
steps = 0;
cc = (struct callout_cpu *)arg;
CC_LOCK(cc);
while (cc->cc_softticks != ticks) {
while (cc->cc_softticks - 1 != ticks) {
/*
* cc_softticks may be modified by hard clock, so cache
* it while we work on a given bucket.